1. 2016;19;E775-E780High-Resolution Three-Dimensional Computed Tomography for Assessing Complications Related to Intrathecal Drug Delivery
   Observational Study
   Matthias Morgalla, MD, PhD, Marcos Fortunato, MD, Ala Azam, BS, Marcos Tatagiba, MD, PhD, and Guillherme Lepski, MD, PhD.

BACKGROUND: The assessment of the functionality of intrathecal drug delivery (IDD) systems remains difficult and time-consuming. Catheter-related problems are still very common, and sometimes difficult to diagnose.

OBJECTIVES: The aim of the present study is to investigate the accuracy of high-resolution three-dimensional computed tomography (CT) in order to detect catheter-related pump dysfunction.

STUDY DESIGN: An observational, retrospective investigation.

SETTING: Academic medical center in Germany.

METHODS: We used high-resolution three dimensional (3D) computed tomography with volume rendering technique (VRT) or fluoroscopy and conventional axial-CT to assess IDD-related complications in 51 patients from our institution who had IDD systems implanted for the treatment of chronic pain or spasticity.

RESULTS: Twelve patients (23.5%) presented a total of 22 complications. The main type of complication in our series was catheter-related (50%), followed by pump failure, infection, and inappropriate refilling. Fluoroscopy and conventional CT were used in 12 cases. High-resolution 3D CT VRT scan was used in 35 instances with suspected yet unclear complications.

Using 3D-CT (VRT) the sensitivity was 58.93% – 100% (CI 95%) and the specificity 87.54% – 100% (CI 95%).The positive predictive value was 58.93% – 100% (CI 95%) and the negative predictive value: 87.54% – 100% (CI 95%).

Fluoroscopy and axial CT as a combined diagnostic tool had a sensitivity of 8.3% – 91.7% (CI 95%) and a specificity of 62.9% – 100% (CI 95%). The positive predictive value was 19.29% – 100% (CI 95%) and the negative predictive value: 44.43% – 96.89% (CI 95%).

LIMITATIONS: This study is limited by its observational design and the small number of cases.

CONCLUSION: High-resolution 3D CT VRT is a non- invasive method that can identify IDD-related complications with more precision than axial CT and fluoroscopy.